Hi guys

Ages (years) ago I started writing my own 6502 cross assembler, mainly targetd at the WD's 65C02 for my own projects. The 'feel' was initially based off the assembler in the BBC Micro in the 80's, although I've since moved away from that and made it more conformist to what most people expect (using .org to set the assembly address, semi colon for comments, labels with <name>: and $ as the default hex prefix, etc.).
I then left it for quite a long time, picked it up, put it down again and then picked it up again. During that time I converted it to command-line only, rewrote it from the ground up as it was a tad messy, and finally moved it from .NET Framework to .NET Core 5 (so I can later port it to linux - hopefully).
It's mostly complete now, with me clearing up bugs, adding finishing touches and now expanding the supported assembler-base commands.

Supported capabilities listed here: https://6502ca.net/


Now, part of the reason I'm posting this is to get peoples' over-all opinion, but also to ask for any additional suggestions for commands and for a review of the IF command that I've just implemented (based on a previous suggestion from Garth a while back).

There are two versions of IF:


The operator comparison is based on the status flags set by CMP, CPX, CPY.
A full description can be found here (scroll down to the IF command), along with the code assembled: https://6502ca.net/index.php?Commands.

If anyone is interested in taking it for a test run you can download the setup EXE (windows 10 & 11 tested, windows 7 tested but needs SP1 and to be fully patched):
https://6502ca.net/index.php?Downloads (also has a link for downloading the PDF manual).
You can also download a language XML file for notepad++ from: https://6502ca.net/index.php?Editor
Other pages on the site show more information on command-line switches, but basically you can just type (once installed): 6502ca <filename> and it will attempt to assemble your source code. If you don't put a file extension then it assumes '.6502ca'.

If anyone spots any bugs then I'd be interested to know as I haven't had anyone put it through it's paces - just me testing.

Thank you very much for sharing your efforts! I browsed the documentation and it looks quite nice, but I don't have any direct need for a command line assembler at this time ... I'm playing with 'mulators and IDEs like Kowalski for now.

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Got a kilobyte lying fallow in your 65xx's memory map? Sprinkle some VTL02C on it and see how it grows on you!

Mike B. (about me) (learning how to github)

This project is mostly for me to be fair, but thought I'd throw it out there in case it's of use to anyone else.
But thanks for having a look through anyway - appreciated .

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

You're probably right. Also, if you have a product that already works for you why move elsewhere unless there are significant gains? C'est la vie.

One thing which would be very handy is if someone would be ok checking the code my IF command asssmbles? Mostly, it's the signed code I want to be sure of:

This is for the IF <operator/flag> JUMP <address> version:


This is for the IF <operator/flag> BEGIN ... <code> ... END version:

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Cheers for having a look.
The IF command is definitely more about the BEGIN - END version, but thought there was no harm in adding in the JUMP version. The ELSE option is a good idea, so I'll look at adding that in and I'll have a think about the naming convention. Most of my assembler commands (apart from IF) begin with # and so there is a #END command which can be used to denote the end of what you wish to be assembled, so yes, could lead to confusion. I could try curly braces/brackets instead of BEGIN END perhaps? Will have a ponder.
Thanks for the link: I'll have a look through it.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

That's fair enough. The whole BEGIN - END reminds me of Borland Pascal which I used to do a little bit of coding in when I was younger. Good times .
Is there anything else command-wise that you can think of which might be helpful? I was looking at DO LOOP but, much like my JUMP version of IF, it's easy enough to implement without special commands. If there isn't anything else of practical use then I'll do some more bug testing and then draw a line under the project. Next up will be the emulator at that point which will probably be gui based.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Unfortunately I've never used FORTH, although I heard others speak of it in very positive terms. I'll have a look through the page you provided and consider the example you've given - many thanks.

My assembler does allow some expansion - was the following what you had in mind?

Macros:


The above would assemble to:


Also, macros can also nest/call each other:


How a line of source code is processed:


You can use any variable, label or address to jump to. The assembler does the following before assembly:

- Check for sets of double quotes and if found, excludes those parts of the line from the following:
- Check for variables and if found, replace them with the variable values
- Check for hex and binary numbers and replace them with decimal equivilents
- Check for equations and replace them with the results of the equations
Example:

... would result in and that would then be passed to the actual assembler functions.

Another example:

... would result in being passed to the assembler functions.

Just modified the IF command to add a new register option. Will be present in the next release coming soon:

Existing:

(signed) is optional and if present will indicate the comparison involves signed numbers
<comparitor> can be:
equals: eq, equ, =, ==, ==
not equals: neq, !=
less than: LT, <
greater than: GT, >
less than or equals: LTE, <=
greater than or equals: GTE, >=

Flags which can be tested: C, N, Z, V

Syntax:
IF (signed) <comparitor> JUMP <address>
IF (signed) <comparitor> BEGIN
IF (signed) <(!)flag> JUMP <address>
IF (signed) <(!)flag> BEGIN <address>

New register mode:
IF (signed) <register> <comparitor> (#)<value/address> JUMP <address>
IF (signed) <register> <comparitor> (#)<value/address> BEGIN

Example of the new register mode:

This new mode adds in an appropriate CMP <value/address>, CPX <value/address> or CPY <value/address> at the beginning.